'97 F150 with the 4.6L V8. It's not very noticeable except when towing. The gauge starts to bounce around and the oil light will momentarily come on. I was hoping it was the sending unit, but I guess not. Any thoughts?

The problem has been popping up for over a year. But was very inconsistent, until this week. I've had multiple oil changes since it started and did the last one myself, while changing the sending unit.

My best guess. Wiring, make sure it is good to include grounding. Does it act the same in cold weather? Since your oil changes, are you using same brand of oil filter? Just my opinion but some oil filters restrict oil flow during "high pressure" times like when towing or cold start ups. Try using a oil filter from your car dealer is see if any differance just one time.

(did a google search on "Fluctuating Oil Pressure" I was surprized to see what turn up, more than I thought.

* This post was
edited 07/13/12 03:38pm by path1 *

1997 33 ft Holiday Rambler, Never again will a new RV come into this family
2003 25 ft Majestic M/H, Old RV rental Best travel machine we've ever owned.
2013 Arctic Fox Trailer, new to us, no opinion yet

Check beneath the engine oil pan where you may find a wire harness running laterally across near a cross-member. Look at the convoluted black plastic wire harness sheathing to see if it has chafed through and into the wires.

I used a Motorcraft filter bought at Walmart. Yesterday specifically, while towing if I was on the gas the gauge danced around and would finally dip. That's when the light would come on. If I lifted off the gas pedal, the needle would go right back to where it belongs. After unhooking and driving around, no problem. I had the pressure tested, and it is definitely fluctuating.